Recent Posts by Ken Robinson

This article is intended to assist in finding tips and techniques to assist with finding solutions to ORA-1555 errors. The document will cover the following topics: Concepts/Definitions Diagnosing Common Causes/SolutionsConcepts/Definitions The ORA-1555 errors can happen when a query is unable to access enough undo to build a copy of the data at the time the query started. Committed “versions” of blocks aremaintained along with newer uncommitted “versions” of those blocks so...

Concepts/Definitions Oracle SQL*Loader loads data from external files into tables in a database. It has a robust data parsing engine that works with a variety of data formats in the datafile. It can load data locally or across a network connection. It is possible to load multiple datafiles, load data into multiple tables, manipulate data with SQL functions in the same load session.For more pointers on features and limitations with Oracle SQL*Loader review the SQL*Loader...

Concepts/Definitions Changes made to user data or to the database dictionary are recorded in the Oracle redo log files so that database recovery operations can be performed. LogMiner provides an easy-to-use relational interface to redo log files (or archive logs) providing audit and data analysis capabilities. Key capabilities of this interface are • Finding logical corruption • Planning for transaction level recovery • Assistance with tuning and capacity planning• Auditing...

Concepts/Definitions Oracle Data Pump technology enables very high-speed movement of data and metadata from one database to another. Oracle Data Pump is made up of three distinct parts: • The command-line clients, expdp and impdp • The DBMS_DATAPUMP PL/SQL package (also known as the Data Pump API) • The DBMS_METADATA PL/SQL package (also known as the Metadata API)The Data Pump is a server based utility vs. the traditional Export / Import which are client based utilities. The...